Dumping body hoist



July 26, 1938. 'L. s. wooo DUMPING BODY HOIST Original Filed Jan. 2. 1935 2 Sheets-Sheet l I 4. We, \ov Louis S. Wood July 26,1938. L, S. WOOD Re. 20,812

' DUMPING BODY HOIST I Original Filed Jan. 2, 1935 2 Sheets-Sheet 2 I I 7--- I I I, I

I I l Louis 5 Wood I :Z-

Reissued July 26,

UNITED, STATES PATENT OFFICE sun ms'wm om Polntelarmlllch.,as'- I I H signortoGu-Wood Detroit, Mich, a corporation of Iichlgan Origiml No. 2.034.544. and m 11, 1m, 80-

rlal No. 118, January 2, 1835. Application for reissue December 28, 18,37, Serb-l No. 180,844

lOCIaim This invention relates to hydraulic hoist dumping of tiltably mounted bodies. which are mounted upon truck chassis and are tilted rearwardlyso that the contents of the body may be discharg by gravity.

In the present invention the construction which I have devised is designed primarily for the lifting and tilting of bodies which carry very heavy loads, in practice amounting to thirty or more tons. It is a primary object and purpose of the present invention to provide hydraulic hoisting mechanism which is practical and serviceable to take care of such heavy loads.

It is a furtherobject of the invention to provide hoisting mechanism, including a plurality of hydraulic hoists mounted in spaced apart relation to each other transversely of the chassis frame and which are operable through the pumping of oil thereinto from a single pump, a novel and very practical and useful construction being devised.

A still further object is to provide a construction wherein the hoists are spaced apart a greater distance than the width of the chassis frame, and with the hydraulic hoists located outside of the chassis frame members whereby the lifting of the heavily loaded body is uniform and side twist or sway of the body when it is being lifted with its heavy load therein is substantially eliminated, with an elimination of undue or destructive strains upon the hinges connecting the body of the chassis, and upon'other parts of the truck structure.

Another advantage of the present invention is the safety feature which includes a check valve in the highpressure line to the hoisting mechanism, which in case the high pressure line breaks during the tilting movement or at the fully tilted position, prevents the body from dropping to horizontal position. This safety feature is quite essential in that one portion of the high pressure line is necessarily flexible which makes this part of the line more or less fragile.

Many other objects and purposes together with novel mechanisms, constructions and arrangements'of parts for attaining the same will appear as an understanding of the invention is had from the following description taken in connection with the accompanying drawings,'in which;

Fig. 1 is an elevation of the rear end portion of a truck showing a body tiltably mounted thereon and equipped with the hoisting mechanism of my invention, the body being in horizontal position;

Fig. 2 is a fragmentary plan view of the hoist ing mechanism as it is molmted on the chassis side frame members:

v ing of the hoist with the chassis frame and body.

Fig. 4 is a partial side elevation and vertical section of the hoist construction, the section be- 5 ing takensubstantially on the plane of line 4-4 of. Fig. 2; and, v

Fig. 5 is a fragmentary enlarged central vertical section at the lower end of one of the telescoping hoist units and showing the valve control therefor.

Like reference characters refer to like the difierent figures of, the drawings.

The hoist is designed to be mounted on a truck having spaced apart parallel chassis side'frame members I upon which the body 2 for carrying the loadis tiltablymounted on suitable brackets 3 located at the rear of the chassis frame members l. r In the construction of the hoisting mechanism two spaced apart parallel heavy tubes 4 and 5 are located on and above and transversely of the chassis frame members I, being secured thereto by suitable connecting brackets i and at 'each end extending a distance beyond the frame members l. A pair of spaced apart triangularly shaped plates I are carried on and between the tubes 4 and 5 at each outer side of the framemembers I. The plates I havehorizontal upper edges and downwardly and inwardly inclined lower edges (Fig. 3) and the tubes and 5 pass through the plates adjacent the upper corners of the triangles. Both of the tubes 4 and 5 are closed at each end. v

An extensible hoist is located between the plates of each pair of plates I. The hoist-includes an outer cylinder 8 having downwardly projecting ears 9 at its lower end through which a pivot pin iii passes, being carried at its ends by the plates I at the lower corners thereof. Each hydraulic hoist is of the multiple cylinder telescopic type, with a plurality of telescoping cylinders il within the outer cylinder 8 and within each other, as shown in Fig. 5. Theinnermost cylinder I! has its upper end pivotally connected at I! to the underside of the body I. The two cylinders I! of the two telescopic hoists at their upper ends are connected to the lower sides of the body I at widely spaced apart points and at distances from each other greater than the width of the chassis frame as is evident.

The multiple telescopic hoist construction is of the character shown in my application for patent, SerialNo. 367,188, filed May 31st, 1929,

and also shown in my Canadian Patent No. 320,-

parts in the cylinders until a predetermined extension thereof has been had, whereupon with continued operation 'of the oil pump, theexcess oiljilows from the hoist back to an oil reservoir. In the construction shown the return pipes or conduits for the oil are shown at H, one connected at one end near the upper end of each outer cylinder 8,

and both of the pipes H, which are of a flexible I character, being connected at their other ends to the tube 5. A return pipe I! leads from the tube 5 to an oil reservoir tank I6, whereby after the body has been tilted to its extreme position, continued operation of the oil pump causes a return excess of oil from both hoists to the tube 6 and thence back to the reservoir l6.

An outlet pipe ll from the oil reservoir I6 is connected with a suitable gear pump II at the suction side of the pump. Upon-operation of the pump the oil is forced outwardly at the pressure side of the pump through a pipe I! to the tube l. Flexible conduits 20, one for each hoist unit, are

connected each at one end to the tube 4 and at their opposite ends to valve housings 2|, one located underneath each telescopic hoist. A pipe 22 leads from the end of each valve housing 2| opposite the point of connection of the flexible conduit Ill thereto, while a second conduit 23 is connected at a side of each valve housing 2| and at its other end connected with a check valve housing 24 in which a ball check valve 25 is mounted, which preferably is formed integral with the base of the cylinder 8 of each hoist unit (see Fig. 5).

Within the valve housing 2|, which has an inlet and two outlets as shown, a rotatable valve 26' is mounted to which an operating arm 21 is connected. Rods ll, joined with the' outer ends of the two arms 21 for the two valves used with the two telescopic hoists, extend forward from the arms 21 and are connected with the outer ends of arms 29 mounted upon a shaft 30 mounted for rocking movements on suitable simultaneously operated to close passage either to the pipes 22 or the conduits 23.

The pump i8 is driven by a shaft 34 which'has a suitable operative connection with the trans- -misslon mechanism of the truck housed within a transmission housing 35 as shown in Fig. 1. The power take-oi! from the transmission mechanism to the shaft SI. and the manual control for connecting the transmission mechanism with the I pump drive shaft 34 is not shown, as it is common and well known in hydraulic hoist dumping mechanism wherein the engine of a truck drives the transmission mechanism and a suitable selective manually operated power take-oi! mechanism is provided for selectively connecting the gear pump drive with the truck transmission.

To tilt the body and dump its contents valves 26 should be inthe position shown in Fig. 5. Upon connecting the drive shaft 34 for the pump with the transmission which in turn is driven by the engine of the truck, oil is pumped through the pipe "I to the tube I and through the two flexible tubes 20, passing through the valve housings 2| and the tubes, 23 to the telescoping hoists which are extended to lift and tilt the body.

some

Such extension of the hoist continues until the predetermined limit of extension is reached,

whereupon continued pumping of oil through the hoists results in the overflow or excess of oil pumped passing through the flexible tubes I4 to 'the tube 5 and thence back through the pipe l5 to the reservoir It. If the engine is stopped or the gear pump l8 disconnected from the transmission the oil in the hoist cannot pass backward through the tubes 22 because stopped by valve 26. Nor,can itreturn through the conduits 23 as the ball valves 25 drop and seat so as to block any passage backward. Thus the body will be held in any position to which it is elevated so long as the valves 25 are as shown in Fig. 5.

To lower the body after it has been once elevated the lever 33is moved so as to turn arms 21 thus opening passages between the tubes 22 and the flexible conduits 20'. The oil returns through the conduits Ill, tubes I and the pipes ll, through the pump and thence through the pipe l1 to'the reservoir IS, the pump being of the type or character which permits a return of oil reversely through the pump.

With this construction a particularly heavy duty hoist structure is provided and one which, because of the novel manner of mounting the same, serves to resist tendency to sidewise twist or strain of the body. The simultaneous extension of the hoists is attained through the novel structure described with the use of one oil pump whereby the pressures of oil acting on the hoists are the same in both hoists. This construction has been used in practice and has proven particularly satisfactory for trucks having bodies which carry very heavy loads many times reach-' ing or exceeding thirty tons in amount.

The invention is defined in the appended claims and is to be considered comprehensive of all forms of structure coming within their scope.

I claim:

1. In combination, atruck having a truck frame, a body tiltably mounted'thereon, a hoist supporting structure including. spaced apart transverse members located on and above the truck frame and extending at their ends beyond thesides thereof, a pair of spaced apart vertical plates carried by and between said transverse members at each end thereof outsidethe truck frame, an extensible hydraulic, hoist pivotally mounted on and located between the plates of each pair of plates, connections between the upper ends of the hoists andthe body and means for simultaneously extending and retracting the hoists.

2. In a construction of the class described, a vehicle chassis frame, two spaced apart tubular supports having closed ends mounted transversely on and above the frame, hoist supporting means extending between saidsupports, extensible and retractible hydraulic hoists carried by said hoist supporting means a liquid receptacle, means for pumping liquid-therefrom into said hoists to extend the hoists to predetermined positions, means connecting the upper ends of the hoist to the body/{liquid overflow tubular connections from said hoists to one of the tubular supports, and a pipeiconnecting said tubular support with the liquid receptacle.

3. In combination, a vehicle chassis frame, two

spaced apart horizontal tubular supports car-,

'.led on and across the chassisframe, said tubular supports having closed ends, a plurality of hoist supporting means carried on and between ma tubular supports, a hydraulic cylindrical extensibie hoist carried by each of said plurality of hoist supporting means, means connecting the upper ends of the hoists to the lower side of the body, a liquid holding receptacle, a pump. connections for supplying the same with liquid from said receptacle, connections from said'pump to one of said tubular supports for pumping liquid into and through the tubular support, and a tubular connection from said tubular support to the lower end of each hoist for carryingliquid pumped simultaneously to the lower ends of the hoists to extend the same and lift'the body.

4:. A construction containing the elements in combination defined in claim 3, each of said hoists having an overflow connection in the form of a tubular conduit extending between each hoist and the other of said tubular supports, whereby liquid pumped, after the hoists have been extended a predetermined distance, through said tubular connections to said tubular support, and a pipe connecting said second tubular support with the liquid receptacle.

5. In combination, a truck frame, a bodytiltably mounted thereon, spaced apart transverse supports carried on and across the track frame, one of said transverse supports being hoilow, said supports, an extensible hydraulic hoist mounted on and between the plates of each pair of plates, connections between the upper end of the hoist and the body and means for supplying the hydraulic hoist with pressure fluid which flows through the hollow transverse suppom v 8. In combination, a vehicle chassis frame, having side members, a body tiltably mounted thereon, two spaced apart horizontal transverse supportsearriedonandabovesaidsidemembersand extending beyondthesaidside members, two pairs ofplatuorthelikespacedfromeachothercarriedbythecantileverportions ofsaidhorisontal supports and extending between said horizontal supports and having intermediate lower portions extending a distance below said supports and belowthelowersideofthetruckframe,anextensibie cylindrical hydraulic hoist having dependinge'ars,apivotpinextendingthroughsaid earsandthelowerportionsoftheplateswhereso ythehoistispivotailymountedatitslowerend onandbetweensaidlowerportionsoftheplatea ofeachpairofpiatcasaidcyiindricalholstbeingsubstantiailymediailylocated betweenthe rupective plates, means connecting the upper endsoftheholstswiththelowersldeof-the bodyandmeansforsuppiyingpresurefiuidfor thehoists.

7. mcombination,atruckhavingatruck frame.abodytiitabiymountedthereon,shoist structureinchslingmembers two pairs of vertical plates carried by.

extending outwardly beyond the sides of the truck frame, a pair of spaced apart supporting members mounted between and connected to said members forming a box frame extension at each side of the truck frame extensible hydraulic hoists, means I pivotally mounting said hoists in said box frame extensions, said box.frame extensions being interconnected across said truck frame, connections between the upper ends of the hoists and the body, and means for simultaneously extending and retracting the hoists.

8. In combination a truck having a truck frame, a body tiltably mounted thereon, a hoist supporting structure including box frame structures extending outwardly beyond the sides of said frame, said structure being interconnected across said frame forming a unit resting on the top thereof, means for securing said unit to said frame, extensible hydraulic hoists, means pivotaily mounting said hoists in said box structures, connections between the upper ends of the hoists and the body. and means for simultaneously extending and retracting the hoists.

9. In combination. a truck having a truck frame, a body tiltably molmted thereon, a hoist supporting structure having supporting portions projecting outwardly beyond the sides of the frame at each side of the frame and having an interconnecting portion disposed parallel to the sides of the frame and spaced outwardly therefrom, said interconnecting portion at each side oftheframeformingthesupportfortheouter trunnion of a cylindrical hydraulic hoist means, means at each side of the frame spaced inwardly from said interconnecting portion forming the bearing for the inner trunnion of said hoist means, an extensible hydraulic hoist means pivto and located between said inportion and said last named means beyond each slide of the'frame, connections between theupperendsofthehoistsandthebody.

means for simultaneously extending and retract ingthehoists,saidsupportingprojectingportionsbeingacrosssaidframsto formaunitconstruction.

10.In combintioma truckhaving struck frame, a body tiltably mounted thereon, aunitaryhoistlupporflngstructureinciuding box frame structures extending outwardly beyond thesidesofsaidframe,saidstructuresbeinginterconnectedacrosssaidframe,extensiblehydraulic hoists, means pivotaily mounting said hoistsinsaidhoxstnictures,meansdirectlyoonnectingtheupperendsofthehoists andthe bodywherebytheweightofthebodyissupporteddirectiyonthehoists,andmeansfor lslifl nlmultaneously extending and retracting the more a woon. 

